Drilling method and apparatus



June 23, 1953 R. G. PETER DRILLING METHOD AND APPARATUS Filed Dec. 5. 1949 ATTR/VEYS Patented June 23,a 1953 UNITED STATES DRILLING METHOD AND APPARATUS Robert G. Peter, Houston, Tex., assigner tol Reed Houstom Tex., a corpo- Roller Bit Company,

ration of Texas Application December 5, 1949, Serial No. 131,151

This invention relates generally to drilling methods and apparatuses and particularly to methods and apparatuses for drilling deep wells in the earth.

Conventional deep well drilling equipment includes a drill stem to the lower end of which is connected a bit having blade cutters, diamond cutters or roller cutters mounted on bearings.

As the bit isrotated, mud laden drilling Vfluid is pumped down through the drill stem and through nozzles in the bit, and it rises upwardly in the space between the drill stem and the wall of the hole to carry the cuttings to the surface.

The cuttings of the bit should be removed as quickly as possible in order that the cutters will operate directly upon the bottom of the hole rather than upon an accumulation of cuttings in the bottom of the hole. A fluid, such as mercury, heavier than the formation being drilled, may be placed in the bottom of the bore so that the cuttings will quickly float upwardly in the mercury away from the bottom of the hole. The circulating drilling fluid will then carry the cuttings to the surface of the earth where they may be removed from the drilling fluid byy well-known conventional means.

This invention has for one of its general objects the provision of a new and improved method whereby drilling fluid and a heavier fluid such as mercury or the like may be eiiiciently employed in the drilling of a well.

Another object of the invention is the provision of a new and improved apparatus with which drilling fluid and a heavier fluid such as mercury or the like may be efficiently employed in the drilling of a well.

A specific object of the invention is the provision of a new and improved drill bit.

Other objects will hereinafter appear.

In the accompanying drawings,

Fig. 1 is a view illustrating diagrammatically one form of conventional drilling equipment with which this invention may be used, and

Fig. 2, an enlarged detail sectional view of the preferred embodiment of the new and improved bit provided by this invention.

In rotary drillingwith the conventional equipment diagrammatically illustrated by Fig. 1, the pump I pumps drilling fluid from the slush pit 2 through the pipe 3 and hose connection 4 into the drill stem 5. The drilling fluid flows downwardly through the drill stem 5 and the bit 6 at the bottom, thence upwardly about the drill stem in the bore of the well 'I and the casing `8 from which it isdischarged by the pipe 9 into the slush pit 2. The conventional function of the drilling fluid is to keep the bit 6 cool, to remove the cuttings, and to form a coating on the wall of the bore 1.

In Fig. 2, the bit is shown at 6 connected to the drill stem 5 and having an internal passageway ID in vcommunication with the interior of the drill stem 5. The passageway I0 is centrally disposed and. leading upwardly and outwardly from this passageway are ports II. A ring I2 maybe welded on the bit 6 to form an annular upwardly directed discharge nozzle I2a. In the bottom of the bit are roller cutters I3 and I4, and the bottom of the` drilling fluid passageway IIlv4 may be provided with a relatively small port `I Da through which ajsmall quantity of the drilling fluid will be directed downwardly toward the cutters to assist in keeping'the cutters cool. ,l Inthe bottom of the bore 'I of the well and extending upwardly to a point just below the opening of the nozzle I2a is a heavy fluid I5 such as mercury or the like. The numeral I'I indicates the drilling fluid circulating above the mercury I5. The mercury I5 may be poured into the drill stem 5 at the surface when one of the tool ,joints such as that indicated at I6 is disconnected, as shown by Fig. 1. Since the mercury I5 is'very heavy it will descend to the bottom of the hole. When the tool joint I6 is connected again and the pump I is operated the drilling fluid will move downwardly through the drill stem 5 and internal passageway I0 in the bit 6, The major portion of the drilling fluid will pass outwardly through the ports I I and upwardly through the annular nozzle I2a to carry the cuttings I8 upwardly in the space between the drill stem 5 and the wall of the hole 'l and casing 8 and discharge the same into the slush pit 2 in which the cuttings will be removed from the drilling fluid. A small amount of the drilling fluid will pass through the port I0a and through the mercury I5 to assist in keeping the mercury I5 cool.

It will be apparent from the foregoing that during drilling operations the roller cutters I3 and I4 of the bit 6 will cut into the formation as the bit 6 is rotated. The cuttings I8 will oat upwardly to the top of the column of mercury I5. The drilling fluid I'I issuing upwardly from the annular nozzle I2a will carry the cuttings I8 upwardly to the surface. And if the port Illa is provided it will direct a small part of the drilling fluid downwardly toward the cutters to assist in keeping the mercury I5 cool and the mercury occupied by 'the' Ybit lis known. Fig. '2 illustrates the addition oi a volume of mercury sufcient to cause it to rise on the outside of the bit to a point just below the opening of the nozzle I2a when t-helpumpY I is operated. It will fbe understood that the level of the mercury may be varied.

It will also be understood 'that `the invention is not limited to the preferred embodiment fof the bit herein disclosed. For example the port a may be omitted, and thestructme of .the drilling fluid passageways serving to direct the drilling iiuid upwardly at a point above Ithe bottom of the bit may be varied, and various types fof :cutting elements-may be femployed. Suchvar- `iations and others `will occur to vthose skilled Vin :the .art within `the scope o f :the Vfollowing claims.

1. The method of drilling earth 'fbore holes lwhich consists in .depositing .a lfluid in 'the bottom yof 'the hole having a specic `gravity higher than `the specic v'gravity of .the vformation fbeing drilled, circulating-'a drilling fluid'having'a'specific 'gravity lower than `the specific gravity of :the lfluid wthin the bottom fof 'thefholeyjetting the major portion of said drilling iluidupwardly Ajust -abovethe level ofthe Vbottom hole fluid :to accelerate the removal fof the cuttings therefrom, and discharging a Esmall"portion of said-drilling fluid zdownwardly into the flower portion of said 'bot- 'tom hole -ilu'id to iprovide cooling `of Vthe I'bottom =holefl-ui`d` l p 2. A ldrllbit Eincluding, a v'bit lbody 'having cut- -ting elements lthereon 'and having ran 'axial -passageway vther-ein' with the lower end of the "pas-` sajgeway closed, 4saidfbody `having a 'plurality of upwardly directed passages extending through the. wall thereof 'and having theirlower ends in 'communication `with the lower klportion of vthe passageway "and their Agupper end communicating with `the area 'exteriorly 'of the bit, eandan -annula-r ring `mounted :on the 4exterior of the body and encompassing 'the open upper ends vof said passages, the upper portion vof the ibore iof `the lring"beingspa-ced from thefbodyvto -"form an annular discharge passage about 'the' body and 'with which the upwardly directed passages communicate.

3. A Vdrill bit =as set forth in 'claim K2, where'in 4 the bit body is also formed with a discharge port extending from the lower end of the passageway for discharging a portion of the uid circulating through the passageway downwardly below the bit.

4. The method of drilling a deep well in the earth with a Ydrill stem 'and a bit on the end of ysaid stem which consists fin, depositing a fluid having a specilic gravity greater than the formation being drilled in the bottom of a well in a Yvolume to substantially submerge the drill bit therein, ith'en circulating a drilling fluid of less specific gravity than the fluid in the bottom of fthe -well downwardly rthrough the drill stem and bit, discharging the major portion of the drilling fluid from within the bit in an upward directtion into the body jof heavier fluid within the bottom .of the well, and discharging a minor portion rof the drilling fluid from within the bit in a direction downward -of the bit into the lower end of 'the body of 'heavier fluid ywithin said -lwell to cool the heavier fiiuid.

j5. The `method vof drilling la deep `well in :the earth with a drill stern and a bit on the end of said :stem which `consists in, `depositing mercury'Y in `the Vbottom yof a well -in a volume to substantially submerge the drill bit therein, 'then `circulating a drilling fluid of less specic gravity than the mercury through the well `bore and stem, discharging the major Yportion ofthe drilling iiuid from within "thfefdrill bit iin an `up war-diy directed annular Ypath and into the area exteriorly of the '-bit, and discharging a minor portion of the drilling fluid from within the bit in'fto the lower end of the body of mercury to cool the mercury.

ROBERT G. PETER.

References Cited Ain 'the file `of 'this vpatent :UNITED STATES PATENTS Number Name Date 762,808 lCushing yet al. June 14, 1904 .1,182,134 Bignell M May 9, 1915 :1,338,460 Morrison Apr. 27, 1920 11,525,944 .Stroud -um.-- Mar. 9, ,1925 1,819,646 Loomis Aug. 18, 1931 k2,043,504 Blow s June 9, 1936 .2,254,449 .Mounce Dec. 2, 1941 FOREIGN PATENTS Number Country Date 201,368 .Germany Sept. 8, 1908 .58,849 Switzerland Nov. `l, 191,1 

